You can build a basic shooter game in Python using the PyGame library. This involves setting up a game window, adding a player, shooting bullets, spawning enemies, and detecting collisions.

1. Install Python from python.org and ensure it’s working on your system.

2. Open a terminal or command prompt and run pip install pygame to install PyGame.

3. Import pygame, sys, and random in your Python file, then call pygame.init() to initialize modules.

4. Create a game window using pygame.display.set_mode() and set a title with pygame.display.set_caption().

5. Define player properties (size, position, speed) and draw it using pygame.draw.rect() inside the game loop.

6. Capture keyboard input with pygame.key.get_pressed() to move the player left or right.

7. Create bullet properties (size, speed) and append new bullets to a list when the space bar is pressed.

8. Update bullet positions each frame and remove bullets that move off-screen.

9. Define enemy properties (size, speed) and spawn them at random horizontal positions using a timer.

10. Move enemies downward each frame and remove them when they leave the screen.

11. Implement a collision check function using rect.colliderect() to detect bullet-enemy hits.

12. Remove both the bullet and enemy from their lists when a collision occurs.

13. Fill the screen each frame with a background color, then draw the player, bullets, and enemies.

14. Call pygame.display.flip() to update the display and clock.tick(60) to cap the frame rate.

15. Run the game loop until a quit event is detected, then call pygame.quit() and sys.exit().